Image display device, image display system, and mobile body

ABSTRACT

An image display device includes a display panel, a barrier panel, and a controller. The display panel is configured to be able to form a first display region, to be able to display a right-eye image in a right-eye visible region of the first display region and display a left-eye image in a left-eye visible region of the first display region. The barrier panel is configured to be able to form a first barrier region and to form a light-transmitting portion and a dimming portion in the first barrier region. The controller is configured to display a portion located in the first display region as one parallax image frame including two sub-frames. The controller is configured to form the dimming region in the entire first barrier region during a frame change period including a timing of changing a display from the parallax image frame to a new parallax image frame.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of Japanese Patent Application No.2018-149167 (filed on Aug. 8, 2018), the contents of which areincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to an image display device, an imagedisplay system, and a mobile body.

BACKGROUND

In a related art, there is known an image display device that projects aparallax image onto both eyes of a user by an active barrier to providestereoscopic vision. The number of valid pixels of the parallax imageprojected on the left eye and the right eye of the user is not greaterthan half the number of valid pixels of the display panel. Therefore, aconfiguration is known in which the number of valid pixels of theparallax image is increased by driving the active barrier so that theimages respectively projected on the left eye and the right eye of theuser are exchanged between the even frame and the odd frame, which aredisplayed in one set. This technique is described, for example, in thefollowing paper:

Ayuki Hayashishita, Hideki Kakeya, “Time-Division Multiplexing ParallaxBarrier with Sub-Subpixel Phase Shift”, SID 2018 DIGEST, P-88,1515-1518.

SUMMARY

An image display device according to one embodiment of the disclosureincludes a display panel, a barrier panel, and a controller. The displaypanel is configured to be able to display a plurality of frames. Thebarrier panel is positioned to overlap the display panel and isconfigured to be able to form a one or more light-transmitting portionand a one or more dimming portion by which a traveling direction of atleast part of image light emitted from the display panel is directed toa right eye of a user and a traveling direction of at least part of theimage light is directed to a left eye of the user. The controller isconfigured to be able to control the display panel and the barrierpanel. The display panel is configured to be able to form a one or morefirst display region. The display panel is configured to be able todisplay a right-eye image visually recognized by the user's right eye ina one or more right-eye visible region of the one or more first displayregion. The display panel is configured to be able to display a left-eyeimage visually recognized by the user's left eye in a one or moreleft-eye visible region of the one or more first display region. Thebarrier panel is configured to be able to form a one or more firstbarrier region corresponding to the one or more first display region.The barrier panel is configured to form the one or morelight-transmitting portion and the one or more dimming portion in theone or more first barrier region so that the one or more right-eyevisible region and the one or more left-eye visible region are locatedat different positions in the one or more first display region. Thecontroller is configured to display a portion located in the one or morefirst display region as one parallax image frame including a firstsub-frame and a second sub-frame when displaying two consecutive frameson the display panel. The controller is configured to be able to controlthe display panel and the barrier panel so that the user visuallyrecognizes images displayed in the first sub-frame and the secondsub-frame included in the one parallax image frame as one parallaximage. The controller is configured to be able to control display of theparallax image in the one or more first display region and formation ofthe one or more light-transmitting portion and the one or more dimmingportion in the one or more first barrier region for each parallax imageframe. The controller is configured to form the one or more dimmingportion in entirety of the one or more first barrier region during aframe change period including a timing of changing a display from theparallax image frame to a new parallax image frame.

An image display system according to one embodiment of the disclosureincludes an image display device and a reflective member. The imagedisplay device includes a display panel, a barrier panel, and acontroller. The display panel is configured to be able to display aplurality of frames. The barrier panel is positioned to overlap thedisplay panel and is configured to be able to form a one or morelight-transmitting portion and a one or more dimming portion by which atraveling direction of at least part of image light emitted from thedisplay panel is directed to a right eye of a user and a travelingdirection of at least part of the image light is directed to a left eyeof the user. The controller is configured to be able to control thedisplay panel and the barrier panel. The display panel is configured tobe able to form a one or more first display region. The display panel isconfigured to be able to display a right-eye image visually recognizedby the user's right eye in a one or more right-eye visible region of theone or more first display region. The display panel is configured to beable to display a left-eye image visually recognized by the user's lefteye in a one or more left-eye visible region of the one or more firstdisplay region. The barrier panel is configured to be able to form a oneor more first barrier region corresponding to the one or more firstdisplay region. The barrier panel is configured to form the one or morelight-transmitting portion and the one or more dimming portion in theone or more first barrier region so that the one or more right-eyevisible region and the one or more left-eye visible region are locatedat different positions in the one or more first display region. Thecontroller is configured to display the portion located in the one ormore first display region as one parallax image frame including a firstsub-frame and a second sub-frame when displaying two consecutive frameson the display panel. The controller is configured to be able to controlthe display panel and the barrier panel so that the user visuallyrecognizes images displayed in the first sub-frame and the secondsub-frame included in the one parallax image frame as one parallaximage. The controller is configured to be able to control display of theparallax image in the one or more first display region and formation ofthe one or more light-transmitting portion and the one or more dimmingportion in the one or more first barrier region for each parallax imageframe. The controller is configured to form the one or more dimmingportion in entirety of the one or more first barrier region during aframe change period including a timing of changing a display from theparallax image frame to a new parallax image frame. The reflectivemember is configured to reflect the image light to reach the left eyeand the right eye of the user.

The mobile body according to one embodiment of the disclosure includesan image display system. The image display system includes an imagedisplay device and a reflective member. The image display deviceincludes a display panel, a barrier panel, and a controller. The displaypanel is configured to be able to display a plurality of frames. Thebarrier panel is positioned to overlap the display panel and isconfigured to be able to form a one or more light-transmitting portionand a one or more dimming portion by which a traveling direction of atleast part of image light emitted from the display panel is directed toa right eye of a user and a traveling direction of at least part of theimage light is directed to a left eye of the user. The controller isconfigured to be able to control the display panel and the barrierpanel. The display panel is configured to be able to form a one or morefirst display region. The display panel is configured to be able todisplay a right-eye image visually recognized by the user's right eye ina one or more right-eye visible region of the one or more first displayregion. The display panel is configured to be able to display a left-eyeimage visually recognized by the user's left eye in a one or moreleft-eye visible region of the one or more first display region. Thebarrier panel is configured to be able to form a one or more firstbarrier region corresponding to the one or more first display region.The barrier panel is configured to form the one or morelight-transmitting portion and the one or more dimming portion in theone or more first barrier region so that the one or more right-eyevisible region and the one or more left-eye visible region are locatedat different positions in the one or more first display region. Thecontroller is configured to display the portion located in the one ormore first display region as one parallax image frame including a firstsub-frame and a second sub-frame when displaying two consecutive frameson the display panel. The controller is configured to be able to controlthe display panel and the barrier panel so that the user visuallyrecognizes images displayed in the first sub-frame and the secondsub-frame included in the one parallax image frame as one parallaximage. The controller is configured to be able to control display of theparallax image in the one or more first display region and formation ofthe one or more light-transmitting portion and the one or more dimmingportion in the one or more first barrier region for each parallax imageframe. The controller is configured to form the one or more dimmingportion in entirety of the one or more first barrier region during aframe change period including a timing of changing a display from theparallax image frame to a new parallax image frame. The reflectivemember is configured to reflect the image light to reach the left eyeand the right eye of the user.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view showing a configuration example of an imagedisplay device according to one embodiment;

FIG. 2 is a block diagram showing a configuration example of the imagedisplay device according to one embodiment;

FIG. 3 is a plan view showing a configuration example of a displaypanel;

FIG. 4 is a plan view showing a configuration example of a barrierpanel;

FIG. 5 is a diagram showing an example of how the image display devicelooks to a user;

FIG. 6 is a diagram showing an example of a sub-left-eye image includedin a left-eye image;

FIG. 7 is a diagram showing an example of a sub-right-eye image includedin a right-eye image;

FIG. 8 is a diagram showing a display example of a display panel in afirst sub-frame;

FIG. 9 is a diagram showing a display example of a display panel in asecond sub-frame;

FIG. 10 is a timing chart showing a control timing of a one or morefirst barrier region;

FIG. 11 is a timing chart showing a control timing of a one or moresecond barrier region; and

FIG. 12 is a diagram showing a configuration example of an image displaysystem according to one embodiment.

DETAILED DESCRIPTION

As shown in FIGS. 1 and 2, an image display device 10 according to oneembodiment includes a display panel 20, a barrier panel 30, and acontroller 50. The display panel 20 is configured to be able to displayan image to be visually recognized by a user. The barrier panel 30 isconfigured to allow a part of image light emitted from the display panel20 to reach one of a left eye 5L and a right eye 5R of the user and toallow another part of the image light to reach the other eye of theuser. That is, the barrier panel 30 is configured so that a travelingdirection of at least part of the image light is directed to the lefteye 5L of the user and a traveling direction of at least part of theimage light is directed to the right eye 5R of the user. The barrierpanel 30 may be located on a side closer to the user than the displaypanel 20 or may be located on a side farther from the user than thedisplay panel 20 when viewed from the user. The image light traveling inthe direction determined by the barrier panel 30 can reach the left eye5L and the right eye 5R of the user as different image lights. As aresult, the user can visually recognize different images for each of theleft eye 5L and the right eye 5R. That is, the image display device 10can be configured to project a parallax image onto both eyes of theuser. The parallax image is an image including separate images projectedon each of the left eye 5L and the right eye 5R of the user and is animage that gives parallax to both eyes of the user. The user can see theimage stereoscopically by viewing the parallax image with the left eye5L and the right eye 5R. The direction that gives parallax to both eyesof the user is also called a parallax direction. The parallax directioncorresponds to a direction in which the left eye 5L and the right eye 5Rof the user are lined up.

The controller 50 is configured to be connected to each component of theimage display device 10 to be able to control each component. Thecontroller 50 may include a first controller 51 and a second controller52. The first controller 51 may be configured to be able to control thedisplay panel 20. The second controller 52 may be configured to be ableto control the barrier panel 30. The first controller 51 and the secondcontroller 52 may be configured to be able to be synchronized. The firstcontroller 51 and the second controller 52 may be configured to becontrollable as a master-slave relationship. One of the first controller51 and the second controller 52 may be configured to be controllable asa master and the other may be configured to be controllable as a slave.The controller 50 may further include a higher controller that ispositioned above the first controller 51 and the second controller 52and controls the first controller 51 and the second controller 52.

The controller 50 may be configured as, for example, a processor. Thecontroller 50 may include one or more processors. The processor mayinclude a general-purpose processor that loads a specific program andexecutes a specific function and a dedicated processor specialized for aspecific process. The dedicated processor may include an applicationspecific integrated circuit (ASIC). The processor may include aprogrammable logic device (PLD). The PLD may include an FPGA(Field-Programmable Gate Array). The controller 50 may be either a SoC(System-on-a-Chip) or a SiP (System In a Package) in which one or aplurality of processors cooperate. The controller 50 may be configuredto include a storage unit to store various information, a program foroperating each component of the image display device 10, and the like inthe storage unit. The storage unit may be configured of, for example, asemiconductor memory or the like. The storage unit may be configured tofunction as a work memory of the controller 50.

The display panel 20 is configured to be able to display a plurality ofleft-eye images 23L (see FIG. 6) visually recognized by the user's lefteye 5L, a plurality of right-eye images 23R (see FIG. 7) visuallyrecognized by the user's right eye 5R, and a plane image 24 (see FIG. 8)visually recognized by both eyes of the user. The display panel 20 maybe, for example, a liquid crystal device such as an LCD (Liquid CrystalDisplay). The display panel 20 may be a self-luminous device such as anorganic EL (Electro-Luminescence) or an inorganic EL. If the displaypanel 20 is a self-luminous device, the barrier panel 30 is locatedcloser to the user than the display panel 20.

As shown in FIG. 3, the display panel 20 is configured to be able toform a one or more first display region 21 and a one or more seconddisplay region 22. The one or more first display region 21 includes aplurality of left-eye visible regions 21L visually recognized by theuser's left eye 5L and a plurality of right-eye visible regions 21Rvisually recognized by the user's right eye 5R. The display panel 20 isconfigured to be able to display the left-eye image 23L in each left-eyevisible region 21L and is configured to be able to display the right-eyeimage 23R in each right-eye visible region 21R. That is, the displaypanel 20 is configured to be able to display a parallax image in theplurality of left-eye visible regions 21L and the plurality of right-eyevisible regions 21R. The plurality of left-eye visible regions 21L andthe plurality of right-eye visible regions 21R are aligned in an X-axisdirection. In the present embodiment, the parallax direction isassociated with the X-axis direction. The X-axis direction is alsocalled a horizontal direction or a first direction. A Y-axis directionis also called a vertical direction or a second direction. The one ormore left-eye visible region 21L and the one or more right-eye visibleregion 21R may be located at intervals as illustrated in FIG. 3 or maybe adjacent to each other. The display panel 20 is configured to be ableto display the plane image 24 in the one or more second display region22.

As shown in FIG. 3, the plurality of left-eye visible regions 21L andthe plurality of right-eye visible regions 21R may extend along theY-axis direction or may extend in a direction inclined at apredetermined angle with respect to the Y-axis direction. In otherwords, the plurality of left-eye visible regions 21L and the pluralityof right-eye visible regions 21R may extend along a directionintersecting the parallax direction. The plurality of left-eye visibleregions 21L and the plurality of right-eye visible regions 21R may bearranged alternately along a predetermined direction includingcomponents in the parallax direction. A pitch in which the one or moreleft-eye visible region 21L and the one or more right-eye visible region21R are alternately arranged is also called a parallax image pitch.

The barrier panel 30 is configured so that the image light related tothe plurality of left-eye images 23L reaches the user's left eye 5L andthe image light related to the plurality of right-eye images 23R reachesthe user's right eye 5R. The barrier panel 30 is configured to functionas an active barrier.

As shown in FIG. 4, the barrier panel 30 is configured to be able toform a one or more first barrier region 31 and a one or more secondbarrier region 32. If the barrier panel 30 is located closer to the userthan the display panel 20 when viewed from the user, the barrier panel30 is configured to be able to control the transmittance of the imagelight emitted from the display panel 20. The one or more first barrierregion 31 corresponds to the one or more first display region 21 and isconfigured to be able to control the transmittance of the image lightemitted from the one or more first display region 21. The one or morefirst barrier region 31 is configured to be able to form a plurality oflight-transmitting portions 31T and a plurality of dimming portions 31S.The plurality of light-transmitting portions 31T are configured totransmit the light incident on the barrier panel 30 from the displaypanel 20. The plurality of light-transmitting portions 31T may beconfigured to transmit light with a transmittance equal to or higherthan a first transmittance. The first transmittance may be, for example,100% or may be a value close to 100%. The plurality of dimming portions31S are configured to reduce the light incident on the barrier panel 30from the display panel 20. The plurality of dimming portions 31S may beconfigured to transmit light with a transmittance equal to or lower thana second transmittance. The second transmittance may be, for example, 0%or may be a value close to 0%. The first transmittance is larger thanthe second transmittance. The first transmittance may be a value smallerthan 50%, for example, 10%, as long as a sufficient contrast with thelight transmitted through the plurality of dimming portions 31S can besecured. The second transmittance may be a value larger than around 0%,for example, 10%, as long as a sufficient contrast with the lighttransmitted through the plurality of light-transmitting portions 31T canbe secured. A sufficient contrast ratio may be, for example, 100:1.

If the barrier panel 30 is located farther from the user than thedisplay panel 20 when viewed from the user, the barrier panel 30 isconfigured to be able to control the transmittance of the light incidenton the display panel 20. The plurality of light-transmitting portions31T are configured to transmit the light incident on the display panel20. The plurality of dimming portions 31S are configured to reduce thelight incident on the display panel 20. By doing so, the one or morefirst barrier region 31 is configured to be able to control thetransmittance of the light incident on the one or more first displayregion 21. The intensity of the image light emitted from the displaypanel 20 is controlled based on the intensity of the incident light. Thetraveling direction of the image light emitted from the display panel 20is controlled based on the traveling direction of the incident light.

The barrier panel 30 is configured to form the plurality oflight-transmitting portions 31T to allow the image light related to theplurality of left-eye images 23L to reach the user's left eye 5L and toallow the image light related to the plurality of right-eye images 23Rto reach the user's right eye 5R. The barrier panel 30 is configured toform the plurality of dimming portions 31S so that the image lightrelated to the plurality of left-eye images 23L does not reach or isdifficult to reach the user's right eye 5R and the image light relatedto the plurality of right-eye images 23R does not reach or is difficultto reach the user's left eye 5L. The barrier panel 30 can be configuredsuch that the user visually recognizes the plurality of right-eye images23R with the right eye 5R, while the left eye 5L does not visuallyrecognize or is difficult to visually recognize the plurality ofright-eye images 23R. The barrier panel 30 can be configured such thatthe user visually recognizes the plurality of left-eye images 23L withthe left eye 5L, while the right eye 5R does not visually recognize oris difficult to visually recognize the plurality of left-eye images 23L.The barrier panel 30 is configured to form the plurality oflight-transmitting portions 31T and the plurality of dimming portions31S to define the direction of the image light related to the parallaximage including the plurality of left-eye images 23L and the pluralityof right-eye images 23R.

The barrier panel 30 is configured to form the plurality oflight-transmitting portions 31T and the plurality of dimming portions31S so that the plurality of light-transmitting portions 31T and theplurality of dimming portions 31S are arranged alternately in the X-axisdirection. The barrier panel 30 may be configured to form the pluralityof light-transmitting portions 31T and the plurality of dimming portions31S so that the boundaries between the plurality of light-transmittingportions 31T and the plurality of dimming portions 31S are along theY-axis direction as illustrated in FIG. 4, or along the directioninclined at a predetermined angle with respect to the Y-axis direction.The barrier panel 30 may be configured to form the plurality oflight-transmitting portions 31T and the plurality of dimming portions31S so that the boundaries between the plurality of light-transmittingportions 31T and the plurality of dimming portions 31S are along thedirection intersecting the parallax direction. In other words, thebarrier panel 30 may be configured to form the plurality oflight-transmitting portions 31T and the plurality of dimming portions31S so that the plurality of light-transmitting portions 31T and theplurality of dimming portions 31S are alternately arranged along apredetermined direction including the components in the parallaxdirection.

The shapes of the plurality of light-transmitting portions 31T and theplurality of dimming portions 31S may be determined based on the shapesof the plurality of left-eye visible regions 21L and the plurality ofright-eye visible regions 21R. Conversely, the shapes of the pluralityof left-eye visible regions 21L and the plurality of right-eye visibleregions 21R may be determined based on the shapes of the plurality oflight-transmitting portions 31T and the plurality of dimming portions31S.

The one or more second barrier region 32 corresponds to the one or moresecond display region 22 and is configured to be able to control thetransmittance of the image light emitted from the one or more seconddisplay region 22.

The barrier panel 30 may be configured of a liquid crystal shutter. Theliquid crystal shutter can be configured to be able to control the lighttransmittance based on the applied voltage. The liquid crystal shuttermay be configured of a plurality of pixels and may be configured to beable to control the light transmittance in each pixel. The liquidcrystal shutter may be configured so that a region having a high lighttransmittance or a region having low light transmittance can be formedin any shape. If the barrier panel 30 is configured of a liquid crystalshutter, the plurality of light-transmitting portions 31T may have atransmittance equal to or higher than the first transmittance. If thebarrier panel 30 is configured of a liquid crystal shutter, theplurality of dimming portions 31S may have a transmittance equal to orless than the second transmittance.

The display panel 20 and the barrier panel 30 each include a pluralityof pixels. An arrangement pitch of the plurality of pixels of thedisplay panel 20 and an arrangement pitch of the plurality of pixels ofthe barrier panel 30 may be the same or different. In the presentembodiment, it is assumed that the arrangement pitch of the plurality ofpixels of the display panel 20 and the arrangement pitch of theplurality of pixels of the barrier panel 30 are the same. In this case,each pixel of the display panel 20 and each pixel of the barrier panel30 are associated with each other. Each pixel of the barrier panel 30may be configured to be controllable by any of the plurality oflight-transmitting portions 31T and the plurality of dimming portions31S. The controller 50 may be configured to be able to synchronize thecontrol of each pixel of the display panel 20 with the control of eachpixel of the barrier panel 30 associated therewith. The image qualitycan be improved by configuring to be able to synchronize the controls ofthe pixels of the display panel 20 and the barrier panel 30 that areassociated with each other.

At least a part of the plurality of pixels included in the one or moresecond display region 22 may be configured to be able to display black.The region formed by the pixels displaying black is also called a blackdisplay region. The controller 50 may be configured to form theplurality of dimming portions 31S in a region of the barrier panel 30corresponding to the black display region included in the one or moresecond display region 22. By doing so, the transmittance of the imagelight in the black display region becomes even lower. As a result, theblack display region looks even blacker to the user.

In the configuration illustrated in FIG. 5, the barrier panel 30 islocated between the left eye 5L and the right eye 5R of the user, andthe display panel 20. The barrier panel 30 may be located farther fromthe user than the display panel 20 when viewed from the user. Thebarrier panel 30 is located along the display panel 20. It can be saidthat the barrier panel 30 is located to overlap with the display panel20.

A distance between the left eye 5L and the right eye 5R of the user, andthe barrier panel 30 is also called an observation distance and isrepresented as P. A pitch at which the one or more light-transmittingportion 31T and the one or more dimming portion 31S are arrangedalternately in the X-axis direction is also called a barrier pitch. Thedistance between the left eye 5L and the right eye 5R is also called aninter-eye distance and is represented as E. A distance between thebarrier panel 30 and the display panel 20 is also called a gap and isrepresented as g.

The display panel 20 is configured to form the plurality of left-eyevisible regions 21L that can be visually recognized from the user's lefteye 5L via the plurality of light-transmitting portions 31T, and aplurality of left-eye non-visible regions 22L that cannot be visuallyrecognized or are difficult to be visually recognized from the user'sleft eye 5L due to the plurality of dimming portions 31S. The displaypanel 20 is configured to form the plurality of left-eye visible regions21L and the plurality of left-eye non-visible regions 22L so that theplurality of left-eye visible regions 21L and the plurality of left-eyenon-visible regions 22L are alternately arranged in the X-axisdirection. A position of the boundary between the one or more left-eyevisible region 21L and the one or more left-eye non-visible region 22Lis determined by a position of the boundary between the one or morelight-transmitting portion 31T and the one or more dimming portion 31S,the distance (P) from the barrier panel 30 to both eyes of the user, andthe gap (g).

The display panel 20 is configured to form the plurality of right-eyevisible regions 21R that can be visually recognized from the user'sright eye 5R via the plurality of light-transmitting portions 31T, and aplurality of right-eye non-visible regions 22R that cannot be visuallyrecognized or are difficult to be visually recognized from the user'sright eye 5R due to the plurality of dimming portions 31S. The displaypanel 20 is configured to form the plurality of right-eye visibleregions 21R and the plurality of right-eye non-visible regions 22R sothat the plurality of right-eye visible regions 21R and the plurality ofright-eye non-visible regions 22R are alternately arranged in the X-axisdirection. A position of the boundary between the one or more right-eyevisible region 21R and the one or more right-eye non-visible region 22Ris determined by a position of the boundary between the one or morelight-transmitting portion 31T and the one or more dimming portion 31S,the distance (P) from the barrier panel 30 to both eyes of the user, andthe gap (g).

The display panel 20 may be configured to be able to display theparallax image so that each left-eye image 23L coincides with eachleft-eye visible region 21L. The display panel 20 may be configured tobe able to display the parallax image so that each right-eye image 23Rcoincides with each right-eye visible region 21R. That is, the displaypanel 20 may be configured to be able to display the parallax imagebased on a position of the boundary between the one or morelight-transmitting portion 31T and the one or more dimming portion 31S,the distance (P) from the barrier panel 30 to both eyes of the user, andthe gap (g).

If the plurality of left-eye visible regions 21L and the plurality ofright-eye visible regions 21R overlap at least in part along the X-axisdirection, crosstalk can occur in which a part of the plurality ofleft-eye images 23L is projected onto the right eye 5R or a part of theplurality of right-eye images 23R is projected onto the left eye 5L. Thecrosstalk deteriorates the image quality of the parallax image projectedon the user.

If the plurality of left-eye visible regions 21L and the plurality ofright-eye visible regions 21R are arranged alternately in the X-axisdirection without overlapping each other, the left eye 5L can visuallyrecognize only the plurality of left-eye images 23L, and the right eye5R can visually recognize only the plurality of right-eye images 23R.That is, the barrier panel 30 is configured to form the plurality oflight-transmitting portions 31T and the plurality of dimming portions31S in the one or more first barrier region 31 so that the plurality ofleft-eye visible regions 21L and the plurality of right-eye visibleregions 21R are located at different positions in the one or more firstdisplay region 21. In this case, crosstalk can be reduced. The state inwhich the left eye 5L and the right eye 5R can visually recognize onlythe plurality of left-eye images 23L and the plurality of right-eyeimages 23R, respectively, can be realized when the observation distance(P) is an optimal viewing distance (OVD). The optimal viewing distanceis determined based on the inter-eye distance (E), the gap (g), thebarrier pitch, and the parallax image pitch. In other words, thecontroller 50 may be configured to be able to control the display panel20 and the barrier panel 30 so that the observation distance (P) becomesthe OVD. The controller 50 may be configured to be able to control theshapes and positions of the plurality of light-transmitting portions 31Tand the plurality of dimming portions 31S in the barrier panel 30, andthe shapes and positions of the plurality of right-eye images 23R andthe plurality of left-eye images 23L displayed on the display panel 20so that the observation distance (P) is OVD.

The image display device 10 may further include a configuration such asa camera that acquires positions of the eyes of the user. The controller50 may be configured to be able to control the display panel 20 and thebarrier panel 30 based on positions of the eyes of the user. Crosstalkcan be further reduced by configuring the controller 50 to be able tocontrol the one or more first display region 21 and the one or morefirst barrier region 31 based on the positions of the eyes of the user.The black display region looks even blacker to the user by configuringthe controller 50 to be able to control the one or more second displayregion 22 and the one or more second barrier region 32 based on thepositions of the eyes of the user.

The display panel 20 is configured so that the displayed image can besequentially updated. If the display panel 20 updates the display image,it can be considered that the display panel 20 is displaying a movingimage. The display panel 20 is configured to be able to sequentiallydisplay a plurality of frames, thereby enabling to display a movingimage. In the present embodiment, the entire display region of thedisplay panel 20 is regarded as one frame. When the entire displayregion is one frame, the display panel 20 is configured to be able tosequentially update the images to be displayed on the entire surface ofthe display surface, and thus, is configured to be able to sequentiallydisplay a plurality of frames. The number of frames displayed by thedisplay panel 20 per unit time is also called a frame rate. The framerate may be represented as the number of frames displayed by the displaypanel 20 per second.

The display panel 20 is configured to be able to display a parallaximage including the plurality of right-eye images 23R and the pluralityof left-eye images 23L displayed in the one or more first display region21, and the plane image 24 displayed in the one or more second displayregion 22 in combination as a single frame.

The parallax image includes at least a part of the plurality of left-eyeimages 23L illustrated in FIG. 6 and at least a part of the plurality ofright-eye images 23R illustrated in FIG. 7.

The plurality of left-eye images 23L illustrated in FIG. 6 includes aplurality of first sub-left-eye images 231L and a plurality of secondsub-left-eye images 232L. The plurality of first sub-left-eye images231L and the plurality of second sub-left-eye images 232L do not overlapeach other. In the present embodiment, the plurality of firstsub-left-eye images 231L and the plurality of second sub-left-eye images232L extend in the Y-axis direction and are alternately arranged in theX-axis direction in each left-eye image 23L. It is assumed that thenumber of pixels in the X-axis direction of each of the firstsub-left-eye image 231L and the second sub-left-eye image 232L is set to½ or less of the number of pixels in the X-axis direction of theleft-eye image 23L. In other words, the full-pixel left-eye image 23L isdivided into the first sub-left-eye image 231L and the secondsub-left-eye image 232L, which have half or less of the number of pixelsof the full pixel. The number of pixels of the first sub-left-eye image231L can be different from the number of pixels of the secondsub-left-eye image 232L.

The plurality of right-eye images 23R illustrated in FIG. 7 includes aplurality of first sub-right-eye images 231R and a plurality of secondsub-right-eye images 232R. The plurality of first sub-right-eye images231R and the plurality of second sub-right-eye images 232R do notoverlap each other. In the present embodiment, the plurality of firstsub-right-eye images 231R and the plurality of second sub-right-eyeimages 232R extend in the Y-axis direction and are alternately arrangedin the X-axis direction in each right-eye image 23R. It is assumed thatthe number of pixels in the X-axis direction of each of the firstsub-right-eye image 231R and the second sub-right-eye image 232R is setto ½ or less of the number of pixels in the X-axis direction of theright-eye image 23R. In other words, the full-pixel right-eye image 23Ris divided into the first sub-right-eye image 231R and the secondsub-right-eye image 232R, which have half or less of the number ofpixels of the full pixel. The number of pixels of the firstsub-right-eye image 231R may be different from the number of pixels ofthe second sub-right-eye image 232R.

The plurality of first sub-left-eye images 231L and the plurality offirst sub-right-eye images 231R do not overlap each other. By doing so,the display panel 20 is configured to be able to simultaneously displaythe plurality of first sub-left-eye images 231L and the plurality offirst sub-right-eye images 231R. The plurality of second sub-left-eyeimages 232L and the plurality of second sub-right-eye images 232R do notoverlap each other. By doing so, the display panel 20 is configured tobe able to simultaneously display the plurality of second sub-left-eyeimages 232L and the plurality of second sub-right-eye images 232R.

As shown in FIG. 8, the controller 50 is configured to cause the displaypanel 20 to display a frame including the plurality of firstsub-left-eye images 231L and the plurality of first sub-right-eye images231R as one parallax image in the one or more first display region 21.In the display panel 20, the controller 50 is configured to be able tocontrol the one or more first barrier region 31 of the barrier panel 30so that the display regions of the plurality of first sub-left-eyeimages 231L include the plurality of left-eye visible regions 21L andthe display regions of the plurality of first sub-right-eye images 231Rinclude the plurality of right-eye visible regions 21R. The controller50 may be configured to be able to control the barrier panel 30 so thatthe display regions of the plurality of first sub-left-eye images 231Land the plurality of first sub-right-eye images 231R coincide with theplurality of left-eye visible regions 21L and the plurality of right-eyevisible regions 21R. The controller 50 may be configured to be able tocontrol the barrier panel 30 so that the plurality of left-eye visibleregions 21L and the plurality of right-eye visible regions 21R includethe display regions of the plurality of first sub-left-eye images 231Land the plurality of first sub-right-eye images 231R, respectively.

As shown in FIG. 9, the controller 50 is configured to cause the displaypanel 20 to display a frame including the plurality of secondsub-left-eye images 232L and the plurality of second sub-right-eyeimages 232R in the one or more first display region 21 as one parallaximage. In the display panel 20, the controller 50 is configured to beable to control the one or more first barrier region 31 of the barrierpanel 30 so that the display regions of the plurality of secondsub-left-eye images 232L include the plurality of left-eye visibleregions 21L and the display regions of the plurality of secondsub-right-eye images 232R include the plurality of right-eye visibleregions 21R. The controller 50 may be configured to be able to controlthe barrier panel 30 so that the display regions of the plurality ofsecond sub-left-eye images 232L and the plurality of secondsub-right-eye images 232R coincide with the plurality of left-eyevisible regions 21L and the plurality of right-eye visible regions 21R.The controller 50 may be configured to be able to control the barrierpanel 30 so that the plurality of left-eye visible regions 21L and theplurality of right-eye visible regions 21R include the display regionsof the plurality of second sub-left-eye images 232L and the plurality ofsecond sub-right-eye images 232R, respectively.

When the user views the frame of FIG. 8 and the frame of FIG. 9independently, the user visually recognizes one of the plurality offirst sub-left-eye images 231L and the plurality of second sub-left eyes232L as the plurality of left-eye images 23L. The user visuallyrecognizes one of the plurality of first sub-right-eye images 231R andthe plurality of second sub-right-eye images 232R as the plurality ofright-eye images 23R. In this case, the number of pixels in the X-axisdirection of each of the plurality of left-eye images 23L and theplurality of right-eye images 23R visually recognized by the user is ½times or less of the full pixels.

When the user can see the frame of FIG. 8 and the frame of FIG. 9together, the user can visually recognize the plurality of left-eyeimages 23L, which is a combination of the plurality of firstsub-left-eye images 231L and the plurality of second sub-left-eye images232L. The plurality of left-eye images 23L visually recognized by theuser can be larger pixels than each of the plurality of firstsub-left-eye images 231L and the plurality of second sub-left-eye images232L. The plurality of left-eye images 23L visually recognized by theuser can be regarded as full pixels. The user can visually recognize theright-eye image 23R, which is a combination of the plurality of firstsub-right-eye images 231R and the plurality of second sub-right-eyeimages 232R. The plurality of right-eye images 23R visually recognizedby the user can be larger pixels than each of the plurality of firstsub-right-eye images 231R and the plurality of second sub-right-eyeimages 232R. The plurality of right-eye images 23R visually recognizedby the user can be regarded as full pixels.

The controller 50 is configured to be able to control the display panel20 and the barrier panel 30 so that the user visually recognizes theframe of FIG. 8 and the frame of FIG. 9 as two consecutive framesdisplayed on the display panel 20. By doing so, the user can visuallyrecognize the afterimage of the frame displayed on the first sheet andthe image of the frame displayed on the second sheet as one image. As aresult, in one embodiment, the user can recognize that both thefull-pixel left-eye image 23L and the full-pixel right-eye image 23R aredisplayed. The image composition using afterimages in the eyes of theuser is also called human sensory composition.

If the controller 50 causes the display panel 20 to display the frame ofFIG. 8 and the frame of FIG. 9 as two consecutive frames, the controller50 is configured to cause the display panel 20 to display the portionlocated in the one or more first display region 21 as two sub-frames.The sub-frame contains a parallax image. Among the frames of FIG. 8, theportion located in the one or more first display region 21 is alsocalled a first sub-frame. Among the frames of FIG. 9, the portionlocated in the one or more first display region 21 is also called asecond sub-frame. The controller 50 is configured to cause the displaypanel 20 to display a frame so that one frame includes two sub-frames.That is, the controller 50 is configured to cause the display panel 20to display two frames continuously displayed in the one or more firstdisplay region 21 as one parallax image frame including the firstsub-frame and the second sub-frame. The controller 50 may be configuredto be able to control the one or more first barrier region 31 accordingto the parallax image displayed in the one or more first display region21. The controller 50 may be configured to be able to control theparallax image to be displayed in the one or more first display region21 according to the plurality of right-eye visible regions 21R and theplurality of left-eye visible regions 21L, which have been formed by theone or more first barrier region 31.

The controller 50 may be configured to display the plurality of secondsub-left-eye images 232L in the region where the plurality of firstsub-right-eye images 231R have been displayed at the timing of changingthe display from the first sub-frame to the second sub-frame. Thecontroller 50 may be configured to display the plurality of secondsub-right-eye images 232R in the region where the plurality of firstsub-left-eye images 231L have been displayed at the same timing. Bydoing so, the display positions of the plurality of left-eye images 23Land the plurality of right-eye images 23R can be exchanged. The displaypositions of the plurality of left-eye images 23L are included indisplay attributes of the plurality of left-eye images 23L. The displaypositions of the plurality of right-eye images 23R are included indisplay attributes of the plurality of right-eye images 23R.

The controller 50 is configured to display a plane image frame includingthe plane image 24 in a portion of the displayed frame located in theone or more second display region 22. The controller 50 is configured tobe able to control the one or more second barrier region 32 of thebarrier panel 30 according to the plane image 24 displayed in the one ormore second display region 22.

When the controller 50 displays the frame of FIG. 8 and the frame ofFIG. 9 on the display panel 20 as two consecutive frames, the controller50 is configured to be able to control the portion located in the one ormore second display region 22 as two consecutive plane image frames.

One frame is configured to be displayed simultaneously in the one ormore first display region 21 and the one or more second display region22. That is, the frame rate in the portion displayed in the one or morefirst display region 21 and the frame rate in the portion displayed inthe one or more second display region 22 are configured to be the same.The frame rate of the sub-frame of the parallax image frame displayed inthe one or more first display region 21 is configured to be the same asthe frame rate of the plane image frame displayed in the one or moresecond display region 22. In other words, the frame rate of the parallaximage frame displayed in the one or more first display region 21 isconfigured to be half the frame rate of the plane image frame displayedin the one or more second display region 22.

The image display device 10 according to the present embodiment can beconfigured so that each eye of the user visually recognizes the parallaximage with less image deterioration from full pixels in the one or morefirst display region 21 and can be configured so that the user visuallyrecognizes the plane image 24 having a large frame rate in the one ormore second display region 22. As a result, the image quality of theimage display device 10 is improved.

The controller 50 is configured to be able to control the plurality oflight-transmitting portions 31T and the plurality of dimming portions31S of the barrier panel 30 so that the plurality of right-eye visibleregions 21R are formed in the one or more first display region 21 ineach of the first sub-frame and the second sub-frame. The controller 50may be configured to be able to control the barrier panel 30 so that theplurality of right-eye visible regions 21R formed by the first sub-frameand the plurality of right-eye visible regions 21R formed by the secondsub-frame do not overlap each other. The controller 50 is configured tobe able to control the plurality of light-transmitting portions 31T andthe plurality of dimming portions 31S of the barrier panel 30 so thatthe plurality of left-eye visible regions 21L are formed in the one ormore first display region 21 in each of the first sub-frame and thesecond sub-frame. The controller 50 may be configured to be able tocontrol the barrier panel 30 so that the plurality of left-eye visibleregions 21L formed by the first sub-frame and the plurality of left-eyevisible regions 21L formed by the second sub-frame do not overlap eachother. The controller 50 may be configured to cause the display panel 20to display the plurality of right-eye images 23R and the plurality ofleft-eye images 23L according to the formed plurality of right-eyevisible regions 21R and the formed plurality of left-eye visible regions21L.

In the present embodiment, the controller 50 may be configured to beable to control the display panel 20 and the barrier panel 30 on theassumption that the positions of the eyes of the user are the same whiledisplaying one parallax image frame until a new parallax image frame isdisplayed. That is, when the positions of the eyes of the user aredifferent between the first sub-frame and the second sub-frame, assumingthat the positions of the eyes in each sub-frame are the same, it may beconfigured so that the plurality of right-eye visible regions 21R areformed.

When the controller 50 causes the display panel 20 to display the secondsub-frame included in the same parallax image frame following the firstsub-frame, the controller 50 may be configured to be able to determinethe positions of the plurality of right-eye visible regions 21R in thesecond sub-frame based on the positions of the plurality of right-eyevisible regions 21R in the first sub-frame. In this case, the controller50 is configured to be able to determine the positions of the pluralityof right-eye visible regions 21R without depending on the positions ofthe eyes of the user.

When the controller 50 causes the display panel 20 to display the firstsub-frame of the new parallax image frame following the secondsub-frame, the controller 50 may be configured to be able to determinethe positions of the plurality of right-eye visible regions 21R in thefirst sub-frame without depending on the positions of the plurality ofright-eye visible regions 21R in the second sub-frame. In this case, thecontroller 50 is configured to be able to determine the positions of theplurality of right-eye visible regions 21R, based on the positions ofthe eyes of the user instead of the positions of the plurality ofright-eye visible regions 21R in the second sub-frame displayedimmediately before the display of the first sub-frame.

It is assumed that when the positions of the eyes of the user aredifferent between the first sub-frame and the second sub-frame, theplurality of right-eye visible regions 21R are configured to be able tobe formed based on the positions of the eyes in each sub-frame. In thiscase, in at least one of the plurality of first sub-right-eye images231R displayed in the first sub-frame and the plurality of secondsub-right-eye images 232R displayed in the second sub-frame, aphenomenon that the display is shifted with respect to the plurality ofright-eye visible regions 21R can occur. This phenomenon is caused bythe fact that the plurality of first sub-right-eye images 231R and theplurality of second sub-right-eye images 232R do not overlap each other.When the phenomenon occurs, crosstalk occurs.

When the plurality of second sub-right-eye images 232R are changedaccording to the change in the positions of the eyes of the user, theplurality of first sub-right-eye images 231R and the plurality of secondsub-right-eye images 232R overlaps at least in part. As a result, theimage quality of the plurality of right-eye images 23R seen by the userdeteriorates.

Until here, as a description related to the right eye 5R, the displaymode of the plurality of right-eye images 23R in the plurality ofright-eye visible regions 21R has been described, but the display modeof the plurality of left-eye images 23L in the plurality of left-eyevisible regions 21L can be described identically or similar to thoserelated to the right eye 5R.

According to the image display device 10 according to the presentembodiment, the controller 50 is configured to be able to control thedisplay panel 20 and the barrier panel 30 on the assumption that thepositions of the eyes of the user are the same while one parallax imageframe is displayed. By doing so, crosstalk is less likely to occur andthe quality of the image seen by the user is less likely to deteriorate.

The controller 50 is configured to cause the display panel 20 to displaya portion located in the one or more first display region 21 as oneparallax image frame including the first sub-frame and the secondsub-frame. The controller 50 is configured to be able to control the oneor more first barrier region 31 corresponding to the one or more firstdisplay region 21 according to the change of the sub-frame and thechange of the parallax image frame. That is, the controller 50 isconfigured to be able to control the one or more first barrier region 31for each sub-frame. As shown in FIG. 10, the controller 50 may beconfigured to be able to control the one or more first barrier region 31by dividing each sub-frame into two periods. In FIG. 10, it is assumedthat time advances as the period is located to the right. The controller50 may be configured to be able to control the one or more first barrierregion 31 by dividing the period displaying the first sub-frame into twoperiods represented by P1 and P2. The period represented by P1corresponds to the period from the start of the first sub-frame to theelapse of a predetermined time. The period represented by P2 correspondsto the period from the end of the period represented by P1 to the end ofthe first sub-frame and includes the timing of the change from the firstsub-frame to the second sub-frame. The period represented by P2 is alsocalled a sub-frame change period. The controller 50 may be configured tobe able to control the one or more first barrier region 31 by dividingthe period displaying the second sub-frame into two periods representedby P3 and P4. The period represented by P3 corresponds to the periodfrom the start of the second sub-frame to the elapse of a predeterminedtime. The period represented by P4 corresponds to the period from theend of the period represented by P3 to the end of the second sub-frameand includes the timing of the change from the second sub-frame to thefirst sub-frame. That is, the period represented by P4 includes thetiming of the change from the displayed parallax image frame to a newparallax image frame. The period represented by P4 is also called aframe change period. The controller 50 may be configured to be able tocontrol the one or more first barrier region 31 by dividing the periodin which one parallax image frame is displayed into four periodsrepresented by P1 to P4.

The controller 50 is configured to form the plurality oflight-transmitting portions 31T and the plurality of dimming portions31S in the one or more first barrier region 31 so that the plurality ofright-eye visible regions 21R and the plurality of left-eye visibleregions 21L corresponding to the first sub-frame are formed during theperiod represented by P1. That is, the controller 50 is configured toform, in the one or more first display region 21, the plurality ofright-eye visible regions 21R and the plurality of left-eye visibleregions 21L, which correspond to the plurality of first sub-right-eyeimages 231R and the plurality of first sub-left-eye images 231Ldisplayed in the one or more first display region 21.

During the period represented by P2, the controller 50 is configured tomaintain the state of the one or more first barrier region 31 of thebarrier panel 30 in the period represented by P1.

The controller 50 is configured to form the plurality oflight-transmitting portions 31T and the plurality of dimming portions31S in the one or more first barrier region 31 so that the plurality ofright-eye visible regions 21R and the plurality of left-eye visibleregions 21L corresponding to the second sub-frame are formed during theperiod represented by P3. That is, the controller 50 is configured toform, in the one or more first display region 21, the plurality ofright-eye visible regions 21R and the plurality of left-eye visibleregions 21L, which correspond to the plurality of second sub-right-eyeimages 232R and the plurality of second sub-left-eye images 232Ldisplayed in the one or more first display region 21.

The controller 50 is configured to form a one or more dimming portion31S in entirety of the one or more first barrier region 31 and todisplay the entirety of the one or more first barrier region 31 in blackduring the period represented by P4. The hatching of diagonal linesattached to the period represented by P4 corresponds to displaying theentirety of the one or more first barrier region 31 in black.

The controller 50 is configured to end the control of the periodrepresented by P4 and to end the display of one parallax image frame.The controller 50 is configured to newly start controlling the periodrepresented by P1 and to display a new parallax image frame. Bydisplaying the entirety of the one or more first barrier region 31 inblack before the timing when the displayed parallax image frame isswitched, the user is less likely to feel the afterimage of the framedisplayed before the switching. As a result, image quality is improved.

The controller 50 may be configured to set the transmittance of eachpixel of the one or more first barrier region 31 lower than thetransmittance of the plurality of light-transmitting portions 31T duringthe period represented by P4. Even by making the transmittance of theone or more first barrier region 31 lower than the transmittance of theplurality of light-transmitting portions 31T, the user is less likely tofeel the afterimage of the frame displayed before the switching. As aresult, image quality is improved.

The controller 50 is configured to maintain the state of the one or morefirst barrier region 31 during the period represented by P2. That is,the controller 50 is configured so that the one or more first barrierregion 31 is not displayed in black or the transmittance of the one ormore first barrier region 31 is not lowered before the timing ofswitching from the first sub-frame to the second sub-frame. By doing so,the user easily feels the afterimage of the image displayed in the firstsub-frame. By doing so, the user feels like visually recognizing boththe full-pixel right-eye image 23R and the full-pixel left-eye image23L, which are composed of the afterimage of the first sub-frame and thereal image displayed in the second sub-frame. As a result, image qualityis improved.

The controller 50 is configured to be able to control the barrier panel30 for each period in which the parallax image frame is divided intofour, so that the controller 50 is configured to generate a situation inwhich the user easily feels an afterimage between the sub-frames and isconfigured to generate a situation in which the user is less likely tofeel an afterimage between parallax image frames. As a result, imagequality is improved.

The controller 50 is configured to display a plane image frame includingthe plane image 24 in a portion located in the one or more seconddisplay region 22. The controller 50 is configured to be able to controlthe one or more second barrier region 32 corresponding to the one ormore second display region 22 according to the change of the plane imageframe. That is, the controller 50 is configured to be able to controlthe one or more second barrier region 32 for each plane image frame. Asshown in FIG. 11, the controller 50 may be configured to be able tocontrol each plane image frame in two periods. In FIG. 11, it is assumedthat the time advances as the period is located to the right. Thecontroller 50 may be configured to be able to control the barrier panel30 by dividing the period in which the plane image frame is displayedinto two periods represented by P5 and P6. The period represented by P5corresponds to the period from the start of the plane image frame to theelapse of a predetermined time. The period represented by P6 correspondsto the period from the end of the period represented by P5 to the end ofthe plane image frame and includes the timing of the change from thedisplayed plane image frame to a new plane image frame.

The controller 50 is configured to form the one or more dimming portion31S in the one or more second barrier region 32 to correspond to theblack display included in the plane image 24 displayed in the planeimage frame during the period represented by P5.

The controller 50 is configured to form the one or more dimming portion31S in entirety of the one or more second barrier region 32 and todisplay the entirety of the one or more second barrier region 32 inblack during the period represented by P6. The hatching of diagonallines attached to the period represented by P6 corresponds to displayingthe entirety of the one or more second barrier region 32 in black.

The controller 50 is configured to end the control of the periodrepresented by P6 and end the display of one plane image frame. Thecontroller 50 is configured to newly start controlling the periodrepresented by P5 and display a new plane image frame. The entirety ofthe one or more second barrier region 32 is displayed in black beforethe timing at which the displayed plane image frame is switched, so thatthe user temporarily visually recognizes the black image. By temporarilyvisually recognizing the black image, the user is less likely to feelthe afterimage of the frame that has been displayed before theswitching. As a result, image quality is improved.

The controller 50 may be configured to set the transmittance of eachpixel in the one or more second barrier region 32 lower than thetransmittance of the plurality of light-transmitting portions 31T duringthe period represented by P6. By making the transmittance of the one ormore second barrier region 32 lower than the transmittance of theplurality of light-transmitting portions 31T, the brightness of theimage visually recognized by the user is temporarily reduced. By thetemporarily reduced brightness of the image, the user is less likely tofeel the afterimage of the frame that has been displayed before theswitching. As a result, image quality is improved. A display state inwhich the brightness of an image is reduced is also called alow-luminance display.

The controller 50 can create a situation in which the user is lesslikely to feel an afterimage between the plane image frames by beingconfigured to be able to control the barrier panel 30 for each period inwhich the plane image frame is divided into two. As a result, imagequality is improved.

The period represented by P5 that controls the one or more secondbarrier region 32 is configured to coincide with either the periodrepresented by P1 or the period represented by P3, which controls theone or more first barrier region 31. The period represented by P6 thatcontrols the one or more second barrier region 32 is configured tocoincide with either the period represented by P2 or the periodrepresented by P4, which controls the one or more first barrier region31. The period represented by P6 is also called a plane image framechange period. The plane image frame change period is configured tocoincide with either the sub-frame change period or the frame changeperiod.

The controller 50 is configured to display the entirety of the one ormore first barrier region 31 in black or in low brightness and isconfigured to display the entirety of the one or more second barrierregion 32 in black or in low brightness, during the frame change period.The controller 50 is configured to display the one or more first barrierregion 31 neither in black nor in low brightness but is configured todisplay the entirety of the one or more second barrier region 32 inblack or in low brightness, during the sub-frame change period. By doingso, the user easily feels the afterimage between the sub-frames and theuser hardly feels the afterimage between the parallax image frames andbetween the plane image frames. As a result, image quality is improved.

The unit period of control of the barrier panel 30 may be configured tohave the same length or may be configured to have a different length. Ifthe controller 50 is configured to be operable based on a clock signal,which is a periodic signal, the unit period of control of the barrierpanel 30 is likely to be configured to have the same length. Thecontroller 50 may be configured to be able to control the state of eachpixel of the barrier panel 30 in combination with an enable signal tovary the length of each period. The enable signal may be used to controlthe timing at which the state of each pixel is actually changed. Thecontroller 50 may be configured to write in advance information aboutthe state of each pixel in the period represented by each of P5 and P6at a timing based on the clock signal. The controller 50 may beconfigured to reflect the information written in advance in the state ofeach pixel at the timing when the enable signal is input. The later thetiming when the enable signal is input with respect to the timing whenthe information is written in advance, the later the start of theperiod. As a result, the period is shortened. For example, since thetiming of input of the enable signal in the period represented by P6 islater than the timing of input of the enable signal in the periodrepresented by P5, the period represented by P6 can be shorter than theperiod represented by P5.

The controller 50 may be configured to transition each pixel of thebarrier panel 30 to one of two states, a white display state having thehighest transmittance, and a black display state having the lowesttransmittance. That is, the controller 50 may be configured to be ableto control each pixel of the barrier panel 30 with two gradations, thehighest gradation corresponding to the white display state and thelowest gradation corresponding to the black display state. In thepresent embodiment, it is assumed that the pixel is configured totransition to the black display state when no voltage is applied to thepixel, and the pixel is configured to transition to the white displaystate when a predetermined voltage is applied to the pixel. Thepredetermined voltage may be determined by the specifications of thebarrier panel 30. That is, the controller 50 is configured to apply avoltage of either of the two values to the pixel and not to apply avoltage of an intermediate value. When the pixel is configured to becontrollable with two gradations, the response of the pixel is fasterthan when the pixel is configured to be controllable with intermediategradations. By making the response of the pixel faster, the period forcontrolling the state of the pixel is shortened. For example, theperiods represented by P2, P4, and P6 are shortened.

The controller 50 is configured to display the entirety of the one ormore first barrier region 31 and the one or more second barrier region32 in black or in low brightness during the periods represented by P4and P6. The user visually recognizes a black image or a low-luminanceimage while the entirety of the one or more first barrier region 31 andthe one or more second barrier region 32 is displayed in black or in lowbrightness. By the black display or the low-luminance display, thebrightness of the image seen by the user is configured to change withthe passage of time even within one parallax image frame or one planeimage frame. In this case, the time average value of the brightness ofthe image in one parallax image frame or one plane image framedecreases. That is, the brightness of the image seen by the user isreduced as a whole. By shortening the time for black display orlow-luminance display, the brightness of the image seen by the user isincreased. By shortening the periods represented by P4 and P6, theperiod of black display or low-luminance display is shortened. By doingso, the time average value of the brightness of the image in oneparallax image frame or one plane image frame increases. As a result,the brightness of the image seen by the user is increased.

In the device according to the comparative example, the display panel 20is configured to be displayed in black in a predetermined period whiledisplaying one frame so that the user is less likely to feel theafterimage between the frames. In the comparative example, each pixel ofthe display panel 20 is configured to be controllable with anintermediate gradation. In this case, the response speed of the pixel tothe control changing from the black display to the intermediategradation is slower than the response speed of the pixel to the controlchanging between the two gradations of the black display and the whitedisplay. As a result, in the device according to the comparativeexample, the period of black display is difficult to be shortened. Inother words, the image display device 10 according to the presentembodiment easily shortens the period during which the pixels aredisplayed in black as compared with the device according to thecomparative example. As a result, the image display device 10 accordingto the present embodiment can further increase the brightness of theimage as compared with the device according to the comparative example.

As shown in FIG. 12, the image display system 1 according to anembodiment includes the image display device 10 and a reflective member60. The image display system 1 is configured to display an image on theimage display device 10 and to be able to emit the image light. Theimage light is configured to be reflected by the reflective member 60along a path 62 shown by the broken line and to reach the left eye 5Land the right eye 5R of the user. By configuring the image light to beincident on the eyes of the user, the user can visually recognize theimage displayed on the image display device 10. By visually recognizingthe image light reflected by the reflective member 60, the user visuallyrecognizes the image displayed on the image display device 10 as avirtual image 10Q. The virtual image 10Q is located at the end of thepath extending the path 62 connecting the left eye 5L and the right eye5R of the user and the reflective member 60 to the opposite side of thereflective member 60. The image display system 1 may be a head-updisplay (HUD). The image display system 1 and the image display device10 may provide the user with stereoscopic vision by being directlyviewed by the user.

The image display system 1 according to the present embodiment may bemounted on a mobile body. If the image display system 1 is mounted on amobile body, the user of the image display system 1 may be a driver oroperator of the mobile body, or a passenger. If the image display system1 is mounted on a mobile body, a part of the configuration of the imagedisplay system 1 may be configured to be shared with other devices andparts included in the mobile body. For example, the windshield of themobile body may be configured to be used as a part of the configurationof the image display system 1. For example, the reflective member 60shown in FIG. 1 may be replaced by a windshield of the mobile body.

The “mobile body” in the disclosure includes vehicles, vessels, andaircraft. “Vehicles” in the disclosure include, but are not limited to,automobiles and industrial vehicles and may include railway vehicles,living vehicles, and fixed-wing aircraft traveling on runways.Automobiles include, but are not limited to, passenger cars, trucks,buses, motorcycles, trolleybuses, and the like and may include othervehicles traveling on the road. Industrial vehicles include industrialvehicles for agriculture and construction. Industrial vehicles include,but are not limited to, forklifts and golf carts. Industrial vehiclesfor agriculture include, but are not limited to, tractors, tillers,transplanters, binders, combines, and lawnmowers. Industrial vehiclesfor construction include, but are not limited to, bulldozers, scrapers,excavators, cranes, dump trucks, and road rollers. Vehicles includethose that run manually. The classification of vehicles is not limitedto the above. For example, an automobile may include an industrialvehicle capable of traveling on a road and the same vehicle may beincluded in a plurality of classifications. Vessels in the disclosureinclude marine jets, boats, and tankers. Aircraft in the disclosureincludes fixed-wing aircraft and rotary-wing aircraft.

The configuration according to the disclosure is not limited to theembodiments described above and can be modified or changed in many ways.For example, the functions and the like included in each component andthe like can be rearranged not to be logically inconsistent and aplurality of components and the like can be combined into one ordivided.

The diagram illustrating the configuration according to the disclosureis schematic. The dimensional ratios on the drawings do not always matchthe actual ones.

In the disclosure, the descriptions such as “first” and “second” areidentifiers for distinguishing the configuration. The configurationsdistinguished by the descriptions such as “first” and “second” in thedisclosure can exchange the numbers in the configurations. For example,the first region can exchange the identifiers “first” and “second” withthe second region. The exchange of identifiers takes place at the sametime. Even after exchanging identifiers, the configuration isdistinguished. The identifier may be removed. The configurations withthe identifier removed are distinguished by reference numerals. Basedsolely on the description of identifiers such as “first” and “second” inthe disclosure, it shall not be used for the interpretation of the orderof the configurations, or the rationale for the existence of the lowernumber identifier.

In the disclosure, the X-axis, Y-axis, and Z-axis are provided for theconvenience of explanation and may be interchanged with each other. Theconfiguration according to the disclosure has been described using aCartesian coordinate system composed of the X-axis, the Y-axis, and theZ-axis. The positional relationship of each configuration according tothe disclosure is not determined to be orthogonal.

REFERENCE SIGNS LIST

-   -   1: Image display system    -   5L: Left eye    -   5R: Right eye    -   10: Image display device    -   10Q: Virtual image    -   20: Display panel    -   21L: Left-eye visible region    -   21R: Right-eye visible region    -   22L: Left-eye non-visible region    -   22R: Right-eye non-visible region    -   30: Barrier panel    -   31: First barrier region    -   31T: Light-transmitting portion    -   31S: Dimming portion    -   32: Second barrier region    -   50: Controller    -   60: Reflective member    -   62: Path

The invention claimed is:
 1. An image display device, comprising: adisplay panel configured to be able to display a plurality of frames; abarrier panel positioned to overlap the display panel and configured tobe able to form a one or more light-transmitting portion and a one ormore dimming portion by which a traveling direction of at least part ofimage light emitted from the display panel is directed to a right eye ofa user and a traveling direction at least part of the image light isdirected to a left eye of the user; and a controller configured to beable to control the display panel and the barrier panel, wherein thedisplay panel is configured to be able to form a one or more firstdisplay region, and the display panel is configured to be able todisplay a right-eye image visually recognized by the user's right eye ina one or more right-eye visible region of the one or more first displayregion and is configured to be able to display a left-eye image visuallyrecognized by the user's left eye in a one or more left-eye visibleregion of the one or more first display region, the barrier panel isconfigured to be able to form a one or more first barrier regioncorresponding to the one or more first display region, and the barrierpanel is configured to form the one or more light-transmitting portionand the one or more dimming portion in the one or more first barrierregion so that the one or more right-eye visible region and the one ormore left-eye visible region are located at different positions of theone or more first display region, and the controller is configured tocause the display panel to display a portion located in the one or morefirst display region as one parallax image frame comprising a firstsub-frame and a second sub-frame when displaying two consecutive frameson the display panel, the controller is configured to be able to controldisplay of the parallax image in the one or more first display regionand formation of the one or more light-transmitting portion and the oneor more dimming portion in the one or more first barrier region for eachparallax image frame so that the user visually recognizes imagesdisplayed in the first sub-frame and the second sub-frame included inthe one parallax image frame as one parallax image, and the controlleris configured to form the one or more dimming portion in entirety of theone or more first barrier region during a frame change period comprisinga timing of changing a display from the parallax image frame to a newparallax image frame.
 2. The image display device according to claim 1,wherein when the second sub-frame is displayed following the firstsub-frame in the one or more first display region, the controller isconfigured to determine respective positions of the one or moreright-eye visible region and the one or more left-eye visible region inthe second sub-frame, based on respective positions of the one or moreright-eye visible region and the one or more left-eye visible region inthe first sub-frame, and when the first sub-frame is displayed followingthe second sub-frame in the one or more first display region, thecontroller is configured to determine the respective positions of theone or more right-eye visible region and the one or more left-eyevisible region in the second sub-frame, based on positions of the eyesof the user instead of the respective positions of the one or moreright-eye visible region and the one or more left-eye visible region inthe second sub-frame displayed immediately before a display of the firstsub-frame.
 3. The image display device according to claim 1, wherein thedisplay panel is configured to form a one or more second display region,and the display panel is configured to be able to display a plane imagevisually recognized by both eyes of the user in the one or more seconddisplay region, the barrier panel is configured to be able to form a oneor more second barrier region corresponding to the one or more seconddisplay region, and the barrier panel is configured to be able to formthe one or more light-transmitting portion and the one or more dimmingportion in the one or more second barrier region according to the planeimage displayed in the one or more second display region, and thecontroller is configured to cause the display panel to display a portionlocated in the one or more second display region as two plane imageframes when two consecutive frames are displayed on the display panel,the controller is configured to be able to control display of the planeimage in the one or more second display region and formation of the oneor more light-transmitting portion and the one or more dimming portionin the one or more second barrier region for each plane image frame, andthe controller is configured so that a frame rate of the sub-framecomprised in the parallax image frame and a frame rate of the planeimage frame are a same, and the controller is configured not to form theone or more dimming portion in the entirety of the one or more firstbarrier region and is configured to form the one or more dimming portionin entirety of the one or more second barrier region during a sub-framechange period comprising a timing of changing display from the firstsub-frame to the second sub-frame in the one or more first displayregion.
 4. The image display device according to claim 3, wherein atleast a part of the one or more second display region comprises a blackdisplay region, and the controller is configured to cause the barrierpanel to form the one or more dimming portion in a region correspondingto the black display region in the one or more second barrier region. 5.The image display device according to claim 4, wherein the controller isconfigured to be able to control formation of the one or morelight-transmitting portion and the one or more dimming portion in theone or more second barrier region for each plane image frame based onpositions of the eyes of the user.
 6. The image display device accordingto claim 1, wherein the right-eye image comprises a first sub-right-eyeimage displayed in the first sub-frame and a second sub-right-eye imagedisplayed in the second sub-frame, the left-eye image comprises a firstsub-left-eye image displayed in the first sub-frame without overlappingwith the first sub-right-eye image and a second sub-left-eye imagedisplayed in the second sub-frame without overlapping with the secondsub-right-eye image, and the controller is configured to display thesecond sub-left-eye image in the region where the first sub-right-eyeimage has been displayed and is configured to display the secondsub-right-eye image in the region where the first sub-left-eye image hasbeen displayed, at the timing of changing the display from the firstsub-frame to the second sub-frame.
 7. The image display device accordingto claim 1, wherein the controller comprises a first controller thatcontrols the display panel and a second controller that controls thebarrier panel, and the first controller and the second controller areconfigured to be able to be synchronized.
 8. An image display system,comprising: an image display device comprising a display panelconfigured to be able to display a plurality of frames, a barrier panelpositioned to overlap the display panel and configured to be able toform a one or more light-transmitting portion and a one or more dimmingportion by which a traveling direction of at least part of image lightemitted from the display panel is directed to a right eye of a user anda traveling direction of at least part of the image light is directed toa left eye of the user, and a controller configured to be able tocontrol the display panel and the barrier panel; and a reflectivemember, wherein the display panel is configured to be able to form a oneor more first display region, and the display panel is configured to beable to display a right-eye image visually recognized by the user'sright eye in a one or more right-eye visible region of the one or morefirst display region and is configured to be able to display a left-eyeimage visually recognized by the user's left eye in a one or moreleft-eye visible region of the one or more first display region, thebarrier panel is configured to be able to form a one or more firstbarrier region corresponding to the one or more first display region,and the barrier panel is configured to form the one or morelight-transmitting portion and the one or more dimming portion in theone or more first barrier region so that the one or more right-eyevisible region and the one or more left-eye visible region are locatedat different positions of the one or more first display region, and thecontroller is configured to cause the display panel to display a portionlocated in the one or more first display region as one parallax imageframe comprising a first sub-frame and a second sub-frame whendisplaying two consecutive frames on the display panel, the controlleris configured to be able to control display of the parallax image in theone or more first display region and formation of the one or morelight-transmitting portion and the one or more dimming portion in theone or more first barrier region for each parallax image frame so thatthe user visually recognizes images displayed in the first sub-frame andthe second sub-frame included in the one parallax image frame as oneparallax image, and the controller is configured to form the one or moredimming portion in entirety of the one or more first barrier regionduring a frame change period comprising a timing of changing a displayfrom the parallax image frame to a new parallax image frame, and thereflective member is configured to reflect the image light to reach theleft and right eyes of the user.
 9. The image display system accordingto claim 8, wherein when the second sub-frame is displayed following thefirst sub-frame in the one or more first display region, the controlleris configured to determine the respective positions of the one or moreright-eye visible region and the one or more left-eye visible region inthe second sub-frame, based on respective positions of the one or moreright-eye visible region and the one or more left-eye visible region inthe first sub-frame, and when the first sub-frame is displayed followingthe second sub-frame in the one or more first display region, thecontroller is configured to determine the respective positions of theone or more right-eye visible region and the one or more left-eyevisible region in the second sub-frame, based on positions of the eyesof the user instead of the respective positions of the one or moreright-eye visible region and the one or more left-eye visible region inthe second sub-frame displayed immediately before a display of the firstsub-frame.
 10. The image display system according to claim 8, whereinthe display panel is configured to form a one or more second displayregion, and the display panel is configured to be able to display aplane image visually recognized by both eyes of the user in the one ormore second display region, the barrier panel is configured to be ableto form a one or more second barrier region corresponding to the one ormore second display region, and the barrier panel is configured to beable to form the one or more light-transmitting portion and the one ormore dimming portion in the one or more second barrier region accordingto the plane image displayed in the second display region, and thecontroller is configured to cause the display panel to display a portionlocated in the one or more second display region as two plane imageframes when two consecutive frames are displayed on the display panel,the controller is configured to be able to control display of the planeimage in the one or more second display region and formation of the oneor more light-transmitting portion and the one or more dimming portionin the one or more second barrier region for each plane image frame, andthe controller is configured so that a frame rate of the sub-framecomprised in the parallax image frame and a frame rate of the planeimage frame are a same, and the controller is configured not to form theone or more dimming portion in the entirety of the one or more firstbarrier region and is configured to form the one or more dimming portionin entirety of the one or more second barrier region during a sub-framechange period comprising a timing of changing display from the firstsub-frame to the second sub-frame in the one or more first displayregion.
 11. The image display system according to claim 8, wherein theright-eye image comprises a first sub-right-eye image displayed in thefirst sub-frame and a second sub-right-eye image displayed in the secondsub-frame, the left-eye image comprises a first sub-left-eye imagedisplayed in the first sub-frame without overlapping with the firstsub-right-eye image and a second sub-left-eye image displayed in thesecond sub-frame without overlapping with the second sub-right-eyeimage, and the controller is configured to display the secondsub-left-eye image in the region where the first sub-right-eye image hasbeen displayed and is configured to display the second sub-right-eyeimage in the region where the first sub-left-eye image has beendisplayed, at the timing of changing the display from the firstsub-frame to the second sub-frame.
 12. A mobile body, comprising: animage display system comprising an image display device comprising adisplay panel configured to be able to display a plurality of frames, abarrier panel positioned to overlap the display panel and configured tobe able to form a one or more light-transmitting portion and a one ormore dimming portion by which a traveling direction of at least part ofimage light emitted from the display panel is directed to a right eye ofa user and a traveling direction of at least part of the image light isdirected to a left eye of the user, and a controller configured to beable to control the display panel and the barrier panel; and areflective member, wherein the display panel is configured to be able toform a one or more first display region, and the display panel isconfigured to be able to display a right-eye image visually recognizedby the user's right eye in a one or more right-eye visible region of theone or more first display region and is configured to be able to displaya left-eye image visually recognized by the user's left eye in a one ormore left-eye visible region of the one or more first display region,the barrier panel is configured to be able to form a one or more firstbarrier region corresponding to the one or more first display region,and the barrier panel is configured to form the one or morelight-transmitting portion and the one or more dimming portion in theone or more first barrier region so that the one or more right-eyevisible region and the one or more left-eye visible region are locatedat different positions of the one or more first display region, thecontroller is configured to cause the display panel to display a portionlocated in the one or more first display region as one parallax imageframe comprising a first sub-frame and a second sub-frame whendisplaying two consecutive frames on the display panel, the controlleris configured to be able to control display of the parallax image in theone or more first display region and formation of the one or morelight-transmitting portion and the one or more dimming portion in theone or more first barrier region for each parallax image frame so thatthe user visually recognizes images displayed in the first sub-frame andthe second sub-frame included in the one parallax image frame as oneparallax image, and the controller is configured to form the one or moredimming portion in entirety of the one or more first barrier regionduring a frame change period comprising a timing of changing a displayfrom the parallax image frame to a new parallax image frame, and thereflective member is configured to reflect the image light to reach theleft and right eyes of the user.
 13. The mobile body according to claim12, wherein when the second sub-frame is displayed following the firstsub-frame in the one or more first display region, the controller isconfigured to determine the respective positions of the one or moreright-eye visible region and the one or more left-eye visible region inthe second sub-frame, based on respective positions of the one or moreright-eye visible region and the one or more left-eye visible region inthe first sub-frame, and when the first sub-frame is displayed followingthe second sub-frame in the one or more first display region, thecontroller is configured to determine the respective positions of theone or more right-eye visible region and the one or more left-eyevisible region in the second sub-frame, based on positions of the eyesof the user instead of the respective positions of the one or moreright-eye visible region and the one or more left-eye visible region inthe second sub-frame displayed immediately before a display of the firstsub-frame.
 14. The mobile body according to claim 12, wherein thedisplay panel is configured to form a one or more second display region,and the display panel is configured to be able to display a plane imagevisually recognized by both eyes of the user in the one or more seconddisplay region, the barrier panel is configured to be able to form a oneor more second barrier region corresponding to the one or more seconddisplay region, and the barrier panel is configured to be able to formthe one or more light-transmitting portion and the one or more dimmingportion in the one or more second barrier region according to the planeimage displayed in the one or more second display region, and thecontroller is configured to cause the display panel to display a portionlocated in the one or more second display region as two plane imageframes when two consecutive frames are displayed on the display panel,the controller is configured to be able to control display of the planeimage in the one or more second display region and formation of the oneor more light-transmitting portion and the one or more dimming portionin the one or more second barrier region for each plane image frame, andthe controller is configured so that a frame rate of the sub-framecomprised in the parallax image frame and a frame rate of the planeimage frame are a same, and the controller is configured not to form theone or more dimming portion in the entirety of the one or more firstbarrier region and is configured to form the one or more dimming portionin entirety of the one or more second barrier region during a sub-framechange period comprising a timing of changing display from the firstsub-frame to the second sub-frame in the one or more first displayregion.
 15. The mobile body according to claim 12, wherein the right-eyeimage comprises a first sub-right-eye image displayed in the firstsub-frame and a second sub-right-eye image displayed in the secondsub-frame, the left-eye image comprises a first sub-left-eye imagedisplayed in the first sub-frame without overlapping with the firstsub-right-eye image and a second sub-left-eye image displayed in thesecond sub-frame without overlapping with the second sub-right-eyeimage, and the controller is configured to display the secondsub-left-eye image in the region where the first sub-right-eye image hasbeen displayed and is configured to display the second sub-right-eyeimage in the region where the first sub-left-eye image has beendisplayed, at the timing of changing the display from the firstsub-frame to the second sub-frame.